The California Horse Racing Board says it has identified zilpaterol in a number of Purina Animal Nutrition sweet feed products manufactured in Turlock, Calif. Tests performed by the California Animal Health and Food Safety Laboratory now confirm the board’s assertation. Zilpaterol, typically used as a feed supplement to increase muscle gain in livestock, is a banned substance in horse racing. Molasses-based feeds Purina Race Ready, Purina Strategy, Purina Omoline-200, Country Acres Horse Feed and Country Acres Sweet-12 are affected.

Purina says in a release that zilpaterol is not a safety issue for horses, but since it is a banned substance in racing, the California racing board wants to bring attention to the problem to prevent positive tests and investigate the cause of contamination. According to the racing board, zilpaterol is a beta-2 agonist the Association of Racing Commissioners International classifies zilpaterol as a class 3 drug with a category A penalty.

Purina says it is fully cooperating with the racing board and with the positive identification of low-levels of zilpaterol in certain Purina products, the company is instructing its licensed feed vendors to remove Purina sweet feed products from California Horse Racing Board facilities on a temporary basis. “Given these test results, and as a precautionary measure, we recommend that race horse owners discontinue using Purina horse sweet feed products under the brands Purina or Country Acres that were manufactured at the Purina Turlock plant,” a Purina statement says.

The California Animal Health and Food Safety Laboratory, operated by the University of California-Davis under contact with the California Department of Food and Agriculture (CDFA), detected zilpaterol in a number of post-race samples according to Steve Lyle with the CDFA. “This finding and quick action reflect how seriously feed companies, the California Horse Racing Board and CDFA take feed quality and drug monitoring and use,” he says.

Purina continues its own investigation to identify the source of the zilpaterol contamination. The company says zilpaterol is not used at Turlock or any of its processing plants. “At this time, our investigation has led us to look closely at a single ingredient from a single supplier, impacting the Turlock facility only,” Purina says. The company has confirmed the effected products were manufactured in February 2013 at the Turlock facility under either the Purina or Country Acres labels. Products manufactured at Turlock will have the letters “TRL” in the date code found on the seam of the bag.

“If any licensed trainer or feed company has an unopened bag of any Purina brand from mid-February milled at their Turlock plant, please contact their local CHRB investigator,” advises the California Horse Racing Board. Consumers should contact their feed dealer for dates when replacement Purina product will be available and for an alternative feed in the interim. The company says Purina race-horse feed products made at other Purina plants can be used immediately.

“As soon as tests confirm feed manufactured at Turlock is free of zilpaterol, we will make that product available,” Purina says. “We continue to work in partnership with the CHRB and will continue to provide updates as information is available.”